Valve



May 27, 1947 R. P. MccULLocH r-:TAL 2,421,346.

VALVE Filed Dec. 24, 1945 2 sheets-sheet 1 J2 g a J0 36 jy] i Lr VT l 02D/ MMMW Y May 27, 1947. R. P. MccULLocl-l ET A1. 2,421,346

VALV E Filed Dec. 24, 1945 2 sheets-sheet 2 Patented l`May 27, 1947 l'"UNIT.ED `.STATES PATENT ,OFFICE Robert 1P. McCulloch, Fox Point, and` John .-L.

Ryde, Milwaukee, Wis., as signors, bymesne assignments, to .Borg-Warner .Cor-poration, `Chinage, Ill., a. corporation of Illinois Application 'December 24, 1943, Serial No. 515,575 1 claim. (C1. 251-119) This invention is vdirected to va valve assembly. The invention especially has to do with '.a yvalve particularly suitable .for `superchargers, Icompressors, pumps .and the like,

1t is an object of the present invention to dis lclose an `improved exi'ble valve intended Lprimarily for use inthe outlet of a supercharger.

The principalobject is to providea valve which will `reducethe ypower requirements for operation of a supercharger by eliminating the discharge `baclr pressure through Aa Vportion of the operating cycle.

In this connection, eiorts have been v.made in the past to use 4a valve -for regulating 4the flow of a gas, such as air, .under pressure whereby substantially a one-way iiow is secured. In the case 4of `the Roots type superchargers, operating at relatively high speeds, the use vof a flexible elon- -gatedap type valve has been ybeset with troubles due to the rapidity'of operation, -much ofthe trouble lhaving -been occasioned Tby-the inertia of the material forming the valve as Well as theeiect of air 'pockets' adjacent the flexible elements `retarding the necessary rapid flexing thereof. While Thompson in U. S. Patent No. 247,857. hasl contributed materially to the solution -of the .problem, no one has to applicants knowledge, sucu ceeoled in providing a suitable `val-ve having vflex- -ible, such vas rubber or Neoprene, grid-type elements wherein the inertia and back pressures are substantially reduced -or entirely removed as 1factors seriously retarding the operation of the-valve.

It is an object of the present invention to provide an -im-proved form of valve in which the above-mentioned objections .are overcome. a further obj ect to provide a constructionin which there is created in the vicinity of each valve flexing element, a substantially reduced .pressure area whereby the inertia vof said-flexing element is practically eliminated.

It is another object of the invention to provide an assembly in which use is made of what may be termed reed-like, flexible, reinforced valve elements in vcombination with a yvane assembly, whereby there is created what may be termed a Venturi'action, removing pressure from Vbehind the flexible reed-like valve elements (herein termed wings).

It is a further object to provide a construction which is rel'atvelyinexpensive to manufacture, is

Itis=A i fied Lform-oi .the invention.

l2 easily assembled, is highly emcient for both the flow =oi :air (or other Vpumped medium) in one direction :and the blocking of flow in the other direction. It is*r an object to disclose a device vwhich ris relatively rugged, can be repaired with- Vout much dimculty,` and which is simple.

The invention consists ofthe ynovel constructiOnswarrangements .and devices lto be hereinafter .described .and claimed for carrying out the 4abovestated objectspand such other objectsV as will appearfromthe following description of a .certain preferred embodiment `illustrated in the accompanying .drawings wherein:

Fig. 1 is a sectional, elevational view 'of -a Roo-ts type supercharger having mounted therein a Valve constructed :in accordance with the disclosures of this invention;

Fig. 2 is a fragmentary plan view indicating particularly thevalve arrangement of Fig. 1;

Fig.f3 is `an enlarged Vsectional view taken on the `lines 3-23 of Fig. 2, looking inthe direction ofthe arrows;

Fig 4"is a View taken `on the lines 4--4 Vof Fig. 1 looking in the direction of ythe arrows; and

Fig. i5 vis a cross-sectional view showing a modifLzikecharactzers of .reference designate like parts in itheseveral views of .the drawings.

:Referring more 'in detail to the constructions shown in the various :fig-mes, and kreferring first to Fig. 1, there .is disclosed a supercharger 29,

having rotors 22 and 24., andan inlet port 26 and discharge port 2-8. Itis understood ofcourse that while the disclosure herein is to aV supercharger of `:the Roots type; almost any ,fluid-moving pump or '.oompressor, .and particularly a gas or air pump,

in which there .is need for a valve of this type, would be applicable. However the present. valve is particularly adapted Ato the general use indi- `cated.wherein `:the rotors move at relatively high speeds in ordinary `useV (between I2800 to 15000 revolutions per `mirnlte :the vform shown), and

there are vrcorrespondingly high frequencies of opening and :closing of the valve.

'Seated in the-outletor discharge port r28 of said supercharger, is` `located the valve assembly 3d form-ing the principal subject matter of the present invention As disclosed, this val-ve assembly 30 comprises a Valve'case 3:2 having the horizontal `flange vpor-tion 3l and the 4downwamily depending wall portion 36, the two together forming a boxlike member with open top and bottom adapted to t and be removably retained in said supercharger discharge port as indicated in Fig. 1. Said Valve assembly may be retained in .position by any vconvenient means, such as by the machine screws 38.

The wall 36 along the sides on each side may be provided with a plurality of slots into which are inserted the ends of the bars 4U of the valve member 4! to form a grid-like assembly. These bars 40 may be held in position in such slots by any convenient means, such as by crimping, spot welding, or otherwise. For quantity production the grid may be formed as a unit by stamping or` die casting, for example. Intermediate their ends and from inside wall to inside Wall of the case, the bars 40 are provided with one or more wings or flaps preferably of rubber, Neoprene, or similar flexible material which aps are herein termed wings 42. These wings 42 are preferably shaped as indicated in Fig. 3, and have the normal position where the outside lands or edges 44 of each Valve member 42 seats against the corresponding outside land of the adjacent valve member on each side to close the space between the valve members against the return of air to the interior of the supercharger. It is understood that a hinged flap of relatively non-exible material may be used if desired, although so far as has been determined to the present time, a exible Neoprene or rubber flap is preferable.

When the wings 42 are in the dotted line position shown in Fig. 3, the air pressure from the interior of the supercharger is passing through the air passage 50 between the Wings, and the valve is opened. When the valve members d2 have their outside lands or edges 44 together, the valve is closed.

Upon the pressure in the supercharger reaching an amount great enough to force the wings apart, a Venturi action is immediately set up which hastens the opening of the Valve, reduces the pressure necessary to continue the valve opening operation, and thereby reduces the back pressure on the supercharger, thus cutting down the power requirements necessary for the operation thereof.

It is understood that the Venturi action which is set up immediately when the wings begin to separate, the air pressure in the space 46 is drawn out and the resistance to the wing opening is substantially eliminated. Upon a drop in pressure in the supercharger, the wings drop back into place. This cycle is repeated several thousand times per minute in ordinary operation.

As shown in Fig. 5, the members 48 are provided with one or more air ports 53 leading from the air passage 5!! into the space 46. These air ports prevent a vacuum lock between the wings when the latter are in open or raised position, and likewise assist in the iiow of air into and from said space 46 on the closing and opening of the wings.

The vanes 48 are provided in a grid-like vane assembly comprising a plurality of said vanes spaced from and aligned with said valve members 4|, and serve several purposes among which are to complete the Venturi passages through the` 4 and is centered thereover and spaced therefrom a distance sufficient to allow the Wings 42 to open the desired amount before contacting the vane 48. This contact is clearly illustrated by the dotted line positions of said vanes as shown in Fig. 3.

The area between the adjacent vanes and between the valve elements when the Wings 42 are open to allow the passage of air, retains a Venturi-like action. The Venturi action of said passage in turn results in substantial evacuation of the air from space 46 when the air being pumped by the supercharger is exhausted through the passage 50 between the adjacent valve elementsV and vanes.

For the purposes of ease in manufacture and to eliminate excess expense, the end walls of the case may be slotted as is clearly apparent from Fig. 2, for example, and the vanes are assembled on a pair of cross bars 50a which extend into the slots of said case and may be held therein by any convenient means such for example as by spot welding, press iitting or otherwise attaching. This permits the assembly of the varies to the desired position in one operation after the vanes have been mounted on said cross bars. These vanes may be die cast as an assembly with the cross bars 5E! or molded from plastics.

In operation, each time the rotors 22 and 24 pass the edge of the discharge port, there will be a sudden drop in pressure in the valve due to the back flow of air into the side pockets or buckets of the supercharger. This will cause the wings l2 to close together as above pointed out. As soon as the next rotor plate moves up to a position where the pressure in the supercharger is suiiicient to start the wings 42 flexing, the air pressure behind the wings will be drawn out by the Venturi action and the wings will iiex without substantial back pressure to a position where they approach or touch the Vanes 48. This is true in all forms shown. As soon as these rotor plates pass the edge of the discharge port, back pressure immediately closes the Wings again, thus closing the air passage 50. Ihe cycle is repeated several times during each revolution of the supercharger. The air port 53 increases the certainty of operation and the ease of operation.

It is understood that there is some latitude in the formation of the wings, and the applicants have tried out several forms with successful results. However, the most desirable arrangement so far found by the applicants is that disclosed herein. The bars 40 likewise may be square, triangular, or other shape, but preferably are of the shape shown here which contributes materially to the forming of the adjoining passage 50 between the valve elements into a venturi.

While this invention has been described in detail in its present preferred form or embodiment, it will be apparent to those skilled in the art, after understanding the invention, that various changes and modications may be made therein with'out departing from the spirit or scope thereof. It is aimed in the appended claim to cover all such changes and modications.

We claim:

A valve for a fluid displacement device comprising walls defining an open frame; a first grid and a second grid arranged in superposed spaced relation in said frame; said first grid comprising a plurality of varies each having a cross-section of tear drop formation tapered in the direction of the normal flow of pressure huid; said second grid comprising a plurality of bars aligned with said varies; and a pair of spaced wings on each bar, said wings being inherently flexible and having spear shape end regions tapered in the direction of normal flow of fluid; each pair of said wings being so constructed and arranged that outward 110W of pressure uid is eective to bend each wing in a direction to engage a side face of its spear shape region with the adjacent side of the large end of an adjacent vane, and upon cessation of the ow of pressure fluid said each Wing bends toward and engages its spear shape end region with the spear shape end region of a wing of the adjacent pair of Wings thereby to prevent back ow of the pressure fluid past said wings.

ROBERT P. McCULLOCI-I. JOHN L. RYDE.

REFERENCES CITED The following references are' of record in the le of this patent:

FOREIGN PATENTS 

